How Water and Ion Mobility Affect the NMR Fingerprints of the Hydrated JBW Zeolite: A Combined Computational-Experimental Investigation |
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| Authors: | Siebe Vanlommel Alexander E J Hoffman Dr Sam Smet Dr Sambhu Radhakrishnan Karel Asselman Dr C Vinod Chandran Dr Eric Breynaert Prof Dr Christine E A Kirschhock Prof Dr Johan A Martens Prof Dr Veronique Van Speybroeck |
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| Institution: | 1. Center for Molecular Modeling (CMM), Ghent University, Technologiepark 46, 9052 Zwijnaarde, Belgium;2. Center for Surface Chemistry and Catalysis, KU Leuven, Celestijnenlaan 200 f, PO Box 2461, 3001 Leuven, Belgium |
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| Abstract: | An important aspect within zeolite synthesis is to make fully tunable framework materials with controlled aluminium distribution. A major challenge in characterising these zeolites at operating conditions is the presence of water. In this work, we investigate the effect of hydration on the 27Al NMR parameters of the ultracrystalline K,Na-compensated aluminosilicate JBW zeolite using experimental and computational techniques. The JBW framework, with Si/Al ratio of 1, is an ideal benchmark system as a stepping stone towards more complicated zeolites. The presence and mobility of water and extraframework species directly affect NMR fingerprints. Excellent agreement between theoretical and experimental spectra is obtained provided dynamic methods are employed with hydrated structural models. This work shows how NMR is instrumental in characterising aluminium distributions in zeolites at operating conditions. |
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| Keywords: | ab initio calculations aluminium distribution NMR spectroscopy water mobility zeolites |
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